Tripoli, Lebanon — As hope for a diplomatic solution to Syria's violence fades, international attention is turning to the rebel Free Syrian Army as an alternative means of toppling President Bashar al-Assad.

The FSA has in the past two months become an influential player in the ongoing confrontation between the Assad regime and the Syrian opposition. As the FSA's ranks have swelled with deserters from the regular Syrian forces as well as civilian recruits, it has driven an upsurge in attacks against regime forces.

Rebel FSA troops were reportedly engaged in heavy clashes within five miles of Damascus, the capital and a stronghold of Assad support that until lately has been largely quiet in the 10-month uprising. The FSA has managed to carve out a few tenuous pockets of regime-free territory, although its hold on these areas is fragile given its lack of weapons and ammunition and weak logistical supply chain.

“I believe the FSA is now one of the drivers of the situation. It is going to shape the outcome,” says Jeffrey White, a military analyst with the Washington Institute for Near East Policy (WINEP) and author of a new briefing paper on the FSA. “It has changed the nature of the conflict with the regime, is becoming increasingly identified with the popular opposition within Syria, has shown resilience on the battlefield, and is growing in capabilities and numbers.”

The United Nations Security Council is expected to discuss on Tuesday a draft resolution submitted by Arab and European states that builds upon an Arab League plan for a peaceful transition of power in Syria. Under the plan, Assad would hand power to his deputy pending the formation of a national unity government within two months. Russia, which wields veto power on the UN Security Council, has opposed the resolution as it stands, saying it crosses a “red line” and is tantamount to “regime change.”

Even if Russia were to accept a watered-down version of the resolution, analysts suspect it would make little difference on the ground in Syria, where the gulf between the regime and opposition has become too wide to bridge. Pushing for a UN resolution on Syria is one of the last steps the international community can take before mulling more seriously the military solution that some Syrian activists are openly advocating.

“In reality, a UN resolution is no longer necessary, and might even be counterproductive if it was phrased in such a way as to equate Assad’s mindless crackdown with the legitimate rebellion it succeeded in instigating,” US-based Syrian activist Ammar Abdulhamid wrote in an online newsletter circulated Monday. “What is needed at this stage is the ability and willingness to provide the necessary materiel and logistical support to the rebels and to provide protest leaders with the training and advice necessary to lead the transitional period themselves.”

However, an international decision to support the FSA could risk a backlash from the Syrian regime and its powerful allies in Iran and Hezbollah in Lebanon, risking trouble spilling beyond its borders. Furthermore, while backing an FSA campaign of attrition against the Assad regime may be seen in the West as the least worst solution in the absence of a diplomatic alternative and or international intervention, but the level of violence in Syria would assuredly increase and could last many months before the balance falls in favor of the opposition.

FSA struggling to get enough weapons

Obtaining sufficient arms and ammunition to maintain the struggle against the Assad regime is a daily challenge for the FSA, which has tenuous control of some Damascus suburbs, part of the Idlib province in the north, and the town of Zabadani near the border with Lebanon.

“We need everything,” says Mohammed, an FSA officer in his late 30s who was hiding in the home of a radical Lebanese cleric in Tripoli. “RPGs [rocket-propelled grenades], PKCs [light machine guns], silencers, ammunition. There are so many of us that we need much more than we are getting.”

Some weapons are smuggled through Lebanon’s border with Syria, although the quantity is small and on an individual basis. Other weapons are brought across the border with Turkey, which FSA fighters can cross with relative ease.

Diplomatic sources say that weapons are also crossing into Syria from Iraq on a “tribe to tribe” basis, meaning the Sunni tribes of Iraq’s Al-Anbar province supplying their brethren in eastern Syria. The sources say that the Kurds in northern Iraq are also dispatching armaments to the Kurds of northeast Syria although most of it is being stockpiled for now.

Another valuable source of arms is coming from the regular Syrian Army itself, according to FSA officers.

Some Syrian forces secretly help FSA

Sheikh Zuheir Amr Abassi, spokesman of the Islamic Supreme Council of Syria and a logistical coordinator for the FSA, says there are secret channels of communication between the FSA and soldiers and officers serving in the regular army.

“A potential deserter will contact us and give us his name and rank. We will ask him his job in the army. If he’s of use to us, we tell him to stay where he is so he can smuggle weapons to us or provide us with intelligence. Otherwise, we tell him to desert only when he has a rifle and plenty of ammunition,” he says.

Abassi recounted one example of how an Army officer was recruited into the FSA, handed a Thuraya mobile satellite phone and asked to help prepare for a raid on an arms depot.

“He called us one night and said all was clear. We sent 20 guys with duffel bags to the depot and they filled them with weapons and ammunition,” he says.

37 FSA battalions

There is evidence that some units have managed to obtain relatively advanced systems such as modern Russian anti-tank missiles which can easily penetrate the armor of Syrian BMP fighting vehicles used by front-line troops.

The FSA says its primary mission is to defend protesters on the streets, and it lacks the manpower, arms, equipment, and cohesion to present a conventional challenge to the regular Syrian forces.

But various FSA units are staging a growing number of offensive operations, chiefly hit-and-run guerrilla tactics in a bid to exhaust the regular forces and encourage further desertions thus weakening the regime. The focus of the attacks are against arms depots, relatively vulnerable buses carrying troop reinforcements, and Shabiha militiamen drawn from the minority Alawite sect which forms the backbone of the Assad regime.

Mr. White says that the international community should support the FSA's campaign of attrition by providing "money, arms, especially anti-tank weapons, command and control means, and operational and tactical advice."

There are estimated to be around 37 FSA battalions of which 17 to 23 are militarily active, according to the recent WINEP study.

The FSA claims as many as 40,000 combatants within its ranks, although the study estimates the actual figure to be closer to 4,000 to 7,000. Abassi said that the various battalions are configured in a cellular structure centered on towns and city districts with little or no communication between themselves. The FSA’s leadership is in Turkey but it remains uncertain how much command and control it exerts over the various battalions.

FSA: We need arms, safe haven

The FSA has called for Western assistance in establishing no-fly zones and safe havens from which rebel forces can regroup and plan in reasonable safety. But the West has demonstrated little appetite to intervene in Syria as NATO did last year in Libya. The Syrian military is equipped with multiple advanced anti-aircraft missile systems that could pose a threat to NATO aircraft policing no-fly zones, risking an unwanted escalation with a country whose allies include Iran and Hezbollah.

FSA officers insist they can do the job if they are given arms and a safe haven from which to operate.

“If we were given these ... most of the Army would desert and join us,” Abassi says. “We are not asking the West to intervene [on the ground] but just to give us weapons, safe havens, and no-fly zones. We can do the rest.”

A Western official closely involved with policy toward Syria says the size and strength of the FSA could become the dominant factor in how the Syrian crisis unfolds, if Assad doesn't step down within three months. “It’s a race against time in how quickly the government loses control over key areas of the country, how violent it becomes in those areas, and how hard the regime protection units are willing to fight to keep control of Damascus and Aleppo,” the official says.